That's a consequence of having about the same number of protons (positive charges) and electrons (negative charges).
Thomas Moore, a professor of physics at Pomona College in Claremont, California, uses the principle of relativity to demonstrate why Faraday's Law, which states that a changing magnetic field creates an electric current, is true."Since this is the core principle behind transformers and electric generators, anyone who uses electricity is experiencing the effects of relativity," Moore said. When a direct current (DC) of electric charge flows through a wire, electrons are drifting through the material.
Ordinarily the wire would seem electrically neutral, with no net positive or negative charge.
[Top 10 Inventions that Changed the World]Most metals are shiny because the electrons in the atoms jump from different energy levels, or "orbitals." Some photons that hit the metal get absorbed and re-emitted, though at a longer wavelength. Gold is a heavy atom, so the inner electrons are moving fast enough that the relativistic mass increase is significant, as well as the length contraction.
As a result, the electrons are spinning around the nucleus in shorter paths, with more momentum.
These stations (and the GPS unit in your car) are all experiencing higher accelerations due to gravity than the satellites in orbit.
To get that pinpoint accuracy, the satellites use clocks that are accurate to a few billionths of a second (nanoseconds).Meanwhile, the protons in the first wire are creating a net positive charge, and opposite charges attract.In order for your car's GPS navigation to function as accurately as it does, satellites have to take relativistic effects into account.To the astronaut on board, however, all would seem normal.In addition, the mass of the spaceship would appear to increase from the point of view of people on Earth.[9 Cool Facts About Magnets]Assuming the currents are moving in the same direction, the electrons in the first wire see the electrons in the second wire as motionless.(This assumes the currents are about the same strength).This is because even though satellites aren't moving at anything close to the speed of light, they are still going pretty fast.The satellites are also sending signals to ground stations on Earth.Relativity is one of the most famous scientific theories of the 20th century, but how well does it explain the things we see in our daily lives?Formulated by Albert Einstein in 1905, the theory of relativity is the notion that the laws of physics are the same everywhere. Every time you measure an object's velocity, or its momentum, or how it experiences time, it's always in relation to something else.